<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>flex</title>
    </head>
    <style>
        .box1 {
            border: 1px solid green;
            padding: 5px;
            min-width: 400px;
            /* 弹性布局：父元素属性 */
            display: flex;
            justify-content: space-between;
            flex-wrap: wrap;
        }
        .box1>div {
            /* width: 33%; */
            width: 200px;
            margin: 0px 5px;
            flex-grow: 1;
            border: 1px solid red;
        }
    </style>
    <body>
        
        <div class="box1">
            <div>1</div>
            <div>2</div>
            <div>3</div>
        </div>
        
    </body>
</html>